Use the end behavior of the graph to solve 3x^3+9x^2-12x<0

Answer:
STEP
1
:
Equation at the end of step 1
((3 • (x3)) - 32x2) - 12x = 0
STEP
2
:
Equation at the end of step
2
:
(3x3 - 32x2) - 12x = 0
STEP
3
:
STEP
4
:
Pulling out like terms
4.1 Pull out like factors :
3x3 - 9x2 - 12x = 3x • (x2 - 3x - 4)
Trying to factor by splitting the middle term
4.2 Factoring x2 - 3x - 4
The first term is, x2 its coefficient is 1 .
The middle term is, -3x its coefficient is -3 .
The last term, "the constant", is -4
Step-1 : Multiply the coefficient of the first term by the constant 1 • -4 = -4
Step-2 : Find two factors of -4 whose sum equals the coefficient of the middle term, which is -3 .
-4 + 1 = -3 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -4 and 1
x2 - 4x + 1x - 4
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (x-4)
Add up the last 2 terms, pulling out common factors :
1 • (x-4)
Step-5 : Add up the four terms of step 4 :
(x+1) • (x-4)
Which is the desired factorization
Equation at the end of step
4
:
3x • (x + 1) • (x - 4) = 0
STEP
5
:
Theory - Roots of a product
5.1 A product of several terms equals zero.
When a product of two or more terms equals zero, then at least one of the terms must be zero.
We shall now solve each term = 0 separately
In other words, we are going to solve as many equations as there are terms in the product
Any solution of term = 0 solves product = 0 as well.
Step-by-step explanation:
I hope this helps